Force Potential of the Early Vertical Forearm

Force Potential of the Early Vertical Forearm

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Force Potential of the Early Vertical Forearm

Force potential is the ideal combination of mass and acceleration in the pool. In swimming, the amount of force directly correlates with power, as power also considers time. Power is essential for success since power influences swimming speed (D’Acquisto 2003). Specifically, the arms play a significant role, as arm strength seems to directly influence sprint swimming (Hsu 2000), while the legs potentially do not provide propulsion (Deschodt 1999). This should not suggest the legs are not important, but potentially play a role in drag, the largest inhibitor of swimming speed, and force transfer through the body.

This article only discusses the force potential of the upper extremity, specifically, the force potential of the early vertical forearms, as this area has the larger ceiling for improvement. If you have a large force potential, then you greater ability to swim fast. But, this doesn’t necessarily mean you will swim fast. Also, power is governed by force production, therefore a higher force potential also increases power potential.

Force potential is a continuum, and maximizing force while minimizing drag is essential for swimming. If these potentials come at the cost of biomechanics (not taking advantage of the Serape effect) or posture (distorting body line increases frontal drag) then speed will decrease! This article will only focus on the arms, specifically the early vertical forearm (EVF) as they contribute most to force potential (Keys 2010).

First, it is important to differentiate between the different styles of a freestyle catch, because numerous styles are successful. Each swimmer has an individualized catch which is most appropriate for their body. Finding an individual catch depends on factors including individual anatomy, past experiences (ingrained motor patterns), and the race distance they’re training for. Determining which catch style is ideal for each athlete is the job of the coach and athlete working in unison.

The early a swimmer positions their forearm/arm perpendicular to their line of movement, the higher their force potential (Keys 2010).

The different types of a catch include:

  1. Straight arm catch utilizing the entire arm as a producer of force (high force potential). This difficult movement causes large shoulder stress to stabilize the long lever arm. Moreover, a stable core is ideal for maintaining the position of least drag, making energy transfer vitally important. Fred Bousquet successfully utilized this style.
  2. Low elbow early vertical forearm catch uses the hand, forearm, and part of the upper arm. This style has moderate force potential and shoulder stress. Matt Biondi and Popov used this technique.
  3. High elbow early vertical forearm only uses the hand and force (low force potential) providing the lowest amount of shoulder stress. This is commonly performed by distance swimmers, most recently Sun Yang.

These main options are not built for everyone or for every race. Therefore, individualization is important. For example, if one has poor in water strength, it is unlikely they will succeed with a high force potential stroke. Moreover, if they are unable to move the arm through the water fast, then it is not practical to use the high force potential since it results in more drag.

Next installment will discuss factors inhibiting force potential of the early vertical forearm.


  1. D’Acquisto, L. J., & Berry, J. E. (2003). The relationship between estimated propelling efficiency, peak aerobic power, and swimming performance in trained male swimmers. Medicine and Science in Sports and Exercise, 34(5), Supplement abstract 193.
  2. Hsu, K. M., & Tsu, T. G. (2000). The relationships among shoulder isokinetic strength, swimming speed, and propulsive power in front crawl swimming. Medicine and Science in Sports and Exercise, 32(5), Supplement abstract 1766.
  3. Keys, M., Lyttle, A., Cheng, L., & Blanksby, B. A. (2010). Wave formation as a possible mechanism of propulsion in the freestyle stroke. A paper presented at the XIth International Symposium on Biomechanics and Medicine in Swimming, Oslo, June 16-19, 2010.
  4. Deschodt, V. J. (1999). The relative contribution of arms and legs in humans to propulsion in 25-m sprint front-crawl swimming. European Journal of Applied Physiology and Occupational Physiology, 80, 192-199.

Written By:

Dr. GJohn Mullen


Dr. GJohn Mullen, DPT, CSCS is a World renowned expert and speaker in sports training and rehabilitation. He received his Doctorate in Physical Therapy at USC, as well as the Josette Antonelli Division Service Scholarship, Order of the Golden Cane, and the Order of Areté. At USC, he also performed research on swimming biomechanics and lung adaptations in swimming training. Dr. GJohn has worked with multiple professional and Olympic athletes, helping them earn Olympic medals.

His dedication to research and individualization spurred him to open COR in 2011. Since 2011, Dr. GJohn has been featured in Gizmodo, Motherboard, Stack Magazine, Swimming World Magazine, Swimmer Magazine, USA Swimming, USA Triathlon, Swimming Science, and much more.

He has worked with the numerous colleges and teams regarding rehab and performance. Before his Doctoral program, Dr. GJohn swam on an athletic scholarship at Purdue University.

At Purdue, Dr. GJohn was an Academic Honorable Mention All-American and was awarded the Red Mackey Award and R. O. Papenguh Award. He also won the Purdue Undergraduate business plan and elevator pitch competition, as well as 1st prize with the Indiana Soy Bean Alliance.

Dr. GJohn was born in Centerville, Ohio and was a 24-time high school All-American Swimmer. Dr. GJohn is still a swimmer and holds a Masters Swimming World and Pacific Swimming Record.

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